Why do heat and humidity feel worse than dry heat?

WASHINGTON — The heat and humidity has settled in for the summer in Washington — arriving in the area a bit early thanks to what is known as a “Bermuda high.”

It’s a mass of high pressure that usually forms in late spring to early summer off the southeastern coast and quickly begins playing havoc with the weather.

“Once that area of high pressure forms, what it does is it pumps all that heat and humidity right into the mid-Atlantic,” says Storm Team 4 Meteorologist Lauryn Ricketts. 

This year, the Bermuda high has left the Washington area with July-like weather in mid-June. Ricketts says the air in the D.C. area has become stagnant, with that area of high pressure off the southeast so strong there is just no relief.

“That’s why we have long stretches of summer where it will just be hot and humid here in D.C.,” she explains.

It’s tough for everyone, and can be dangerous for the very young and the very old, whose bodies don’t adjust well to high temperatures

The National Weather Service says in a normal year, approximately 175 Americans die from extreme heat. While that is fairly rare, few of us can escape the extreme discomfort felt when being outside on days when the heat index is skyrocketing

Even diehard runners are well-aware of the risks of exercising is those kinds of conditions.

Lee Firestone — a marathoner and running coach with the Montgomery County Road Runners Club — says the humidity messes with the body’s ability to cool itself, making the heat feel much worse than the thermometer might indicate.

When the body is warm, it produces sweat, which then evaporates and cools the body down. But when it is muggy outside and the air is full of moisture, that sweat cannot evaporate like it would on a dry day. And men, who sweat more, suffer more than women.

Firestone — who is also a sports podiatrist — opts for running early in the morning. But when the air quality starts to deteriorate and a Code Orange day is declared, he says anyone who exercises outside might want to bring it indoors instead.

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